I looked for the reference from a historical post, but can't find it. Someone recommended potting to a larger pot when the plant was already in growth, carefully moving it to a deeper pot keeping the leaves at the same level but giving more room for the roots so the plant would grow better. I think it probably always depends on what it is. I've followed the advice successfully with seedlings that weren't going to grow very fast in the one year pot, but were so small that I didn't want to unpot them. I'm sure that has meant they have bloomed in less time. I waited until they were in good growth to move them up. I've also divided Iris already in growth to thin them out successfully and potted up Lilium species. On the other hand sometimes when I've waited too long to repot and have dumped out a pot the bulb or corm has already started to grow. I'm not sure how much harm this has caused except when the new shoot has broken off in the process. That can't be a good thing, but I couldn't figure out a safe way of determining if a new shoot was grown. After our great freeze a number of years ago, some things that looked like they had died produced new leaves so perhaps they have recovered. In looking for the reference as always with this list I've found conflicting information about what size pot to use, how deep to pot, etc. The correct answer to most questions probably always is, "It depends". ( Factors are your soil mix, your climate including temperatures, rainfall, humidity, your own habits, the size and kind of container, the needs of specific plants, etc.) People have success with a lot of different methods. Mary Sue >John Wickham writes >"Is it perfectly fine to pot up seedlings, for example, as they are >growing?"